究
キュウ, ク, きわ.める, きゅ

research, study

JLPT4 G3 S7 F368

As per 九# (bump up against and bend/curve) + 穴 hole → fumble about in the far reaches of a hole in seeking something (compare 探) → *investigate*; *research* (compare 考) → *master* (a discipline). Compare also 奧.

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